Anaesthetic risk with Anterior Mediastinal Masses:Respiratory and CVS concerns
Niall CT Wilton MRCP FRCANiall CT Wilton MRCP FRCA
Starship ChildrenStarship Children’’s Hospitals Hospital
Auckland New ZealandAuckland New Zealand
Anaesthetic Risk:Information overload
AnteriorMediastinal
MassCases:MorbidityMortality
SymptomsSigns
Size
LocationResp.impact
CVS impact
Cases:Saves
Case series:retrospective
Personal/expert opinion
Today’s objectives
� Case series- and what they tell us
� “Living” anatomy review
� CVS concerns- hidden problems
� Why things go bad with anesthesia
� Looking back to the future- learning from an unfortunate case.
Surgical perspectivePerger L, Lee EY, Shamberger RC J Ped Surg (2008) 43,190-97
� Children with anterior mediastinal masses are at risk for airway compromise. This can be exacerbated by supine position and induction of general anesthesia. General anesthesia should be avoided in patients with tracheal cross-sectional area (TCA) or peak expiratory flow rate (PEFR) less than 50% of predicted for age and sex. Patients with less respiratory compromise can generally safely undergo general anesthesia
CT scans: Tracheal compression and
complications: n=42
� Minimal correlation between symptoms and tracheal CSA
� Both pts with orthopnea had CSA <35%
� No anaesthetic complications when CSA >50%
� But….. Preselection bias!
Shamberger RC et al 1991
Anaesthetic perspective: RespHack HA, Wright NB, Wynn RF
Anaesthesia 2008,63, 837-46 n= 56
� Poor relationship between clinical signs and tumour size or tracheal compression on CT scan
� 20% complication rate (easily managed)
� 5% serious complications( rapid response to avoid disaster)
� Peri-operative respiratory complications were confined to patients with an isolated tracheal cross-sectional area < 30% normal or < 70% + bronchial compression.
� Stridor: only sign that predicted anaesthetic complication
Anaesthetic perspective: CVSHack HA, Wright NB, Wynn RF
Anaesthesia 2008,63, 837-46 n= 56
� Syncope/LOC: 2pts
� 29/56 CTs showed evidence of cardiovascular pathology
� 6/13 cardiac echo’s showed pericardial effusion, vessel compression
� Except for SVC obstruction, CVS symptoms and signs were uncommon.
� Incidence of CVS complications was low (1 pt)
Anaesthetic perspectiveStricker PA, GurnaneyHG, Litman RS
J Clin Anes 2010, 22,159-63 n=46
Echocardiography in children with anterior mediastinal masses:
� 41% (16/39) significant ‘distortion of heart and great vessels’
� 23%(9/39) pericardial effusion
� All had ‘impaired cardiac function’
� No attempt at correlation with symptoms, tumour size or tracheal compression
King DR et al 1997
Sinister symptoms & signs with Anterior Mediastinal Masses
� Orthopnoea:
� Most common reported symptom with adverse events
� Wheezing: Distal airway involvement
� Stridor: proximal airway obstruction
� Syncope: decreased cardiac output
� Upper body oedema/vein distension: SVC obstruction
� Systolic murmer: RVOT/PA compression
Anterior mediastinum
Thymus
Anterior mediastinum
Aorta
Pulmonary outflow tract
Pulmonary artery
RV
Anterior mediastinum
RV
Aorta
SVC
R atrium
Anterior mediastinum:key anatomical points
� R sided lesions likely to affect the SVC
� L sided lesions more likely to affect RVOT/PA
� Azygos vein enters SVC at level of tracheal bifurcation
� Pulmonary artery/RVOT only likely to be involved with tumours extending distal to carina
� R atrial compression also likely in tumour causing RVOT signs
Things to worry about:problem list
1. Proximal airway obstruction
2. Distal airway compression
3. SVC compression/obstruction
4. PA compression/obstruction
5. RVOT/RV compression/obstruction
6. Cardiac compression/pericardial effusion
SVC compression-not always a problem?
Case reports: CVS mortality
Symptoms Problem Cause(compression)
O Co S Cy ineff. CPR PA LMB peric eff.
O Co S ineff. CPR PA PV peric inf.
O Co Cy ineff. CPR PA
O S ineff. CPR (no PM)
O Co St ineff. CPR Cardiac Trachea
O St ineff. CPR SVC and Trachea
Key Points� Anterior mediastinal masses may affect
cardiovascular function as well as causing tracheo-bronchial compression.
� This may occur due to:
� SVC obstruction
� PA/RVOT compression
� Pericardial infiltration/effusion
� If clinical deterioration occurs from cardiovascular causes, conventional CPR is unlikely to be effective
Thoracic contents and anaesthesia
Thoracic contents: Supine awake
Thoracic contents: Supine Anaes
VolumeWeight
InfiltrationLocation
Thoracic contents: Fowler Anaes
� 9-year-old girl, previously well
� 5 weeks lethargy, dyspnoea, weight loss
� Initial diagnosis: mycoplasma?
� Blasts on FBC in Japan
� Parents declined further management
� Homeopathy and Complan from Germany
� First seen at Starship on the previous day
� Reluctantly agreed to be admitted
Pre-op management
� CXR and bloods – no other investigations
� No mention of SVC syndrome
� Commenced steroids + hyperhydration
� Listed for BMA, LP and PICC line
� Not referred to anaesthetist pre-op
Assessment in pre-op
� Comfortable, well-saturated sitting up
� ‘Cannot breathe’ supine - OK on left side
� No stridor
� Distended hand veins – no oedema
� IV in left hand
� CXR: Large anterior mediastinal mass
: trachea slightly pushed left
: small right pleural effusion
What actually happened
� Unable to lie flat for gas induction
� IV induction – LMA
� Left lateral; dexamethasone top-up
� IPPV + PEEP better than spontaneous
� Well-saturated during procedure
� CVS stable throughout
� Waking: recurrent desats needing bagging
� Transiently very agitated
� Much improved when awake
Post-op course
� Left recovery with SpO2 97% on 5 lpm
� PICU updated; documented in notes
� On air and comfortable 3 hours later
� Collapse that evening – “Vasovagal”
� Seen for tachypnoea 1 hr later - resolved
� 2 hours later: moribund, lying prone
� Gasping, blue, SpO2 = “99%”, good A/E
� BP unrecordable, GCS = 5
Code Blue
� Cardiac arrest on commencing IPPV
� Intubated – easy ventilation
� PICC line blocked; peripheral IV removed
� First rhythm = asystole
� EJ cannula sited, 7 doses of adrenaline
� ROSC after 15 mins
� Transferred to PICU
Communication and team work:The way forward
� Full discussion
� Complete evaluation� History and Physical exam
� CT scan
� Echocardiogram
� Joint assessment of risks
� Agreement to proceed
� Its not just about the peri-operative period